Buttonhole sewing machine



J. PIKUL 1,988,460

BUTTONHOLE SEWING MACHINE Jan. 22; 1935-.

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Patented Jan. 22, 1935 UNITED STATES PATENT OFFICE nu'rronnom SEWING MACHINE a corporation. of Maine Application March 25, 1931, Serial No. 525,092

49 Claims. (Cl. 112-252) This invention relates to buttonhole sewing machines and particularly to the means for cutting the threads at the end of the sewing cycle on a buttonhole and holding the cut ends in readiness for the formation of the first stitches at the beginning of the sewing cycle on the next buttonhole.

In the operation of these buttonhole sewing machines the buttonhole stitches are usually formed by concatenating an upper thread which is fed to the work from above the latter, with an under thread which is fed to the work from beneath the latter. Usually a cord is laid along the edge of the buttonhole, which cord is covered by the buttonhole stitches.

One feature of my present invention relates to a novel construction by which the disrupting or severing of the upper thread at the end of the sewing cycle on a buttonhole is accomplished by breaking the thread. An advantage of this construction is that it obviates the use of cutting mechanism and thus reduces the parts necessary to make up the complete sewing machine.

Another feature of the invention relates to a novel holder for holding the end of the upper thread between successive sewing cycles and in proper position for the formation of the first stitches of the second sewing cyclej Another feature of the invention relates to a novel means for cutting the under thread and the stay cord, and of manipulating said thread and stay cord so that at the beginning of each stitch-forming cycle the cutend of said cord and under thread will be correctly presented to the stitch-forming mechanism to enable the first stitches of the sewing cycle to be properly formed. In some buttonhole sewing machines there is a relative movement between the stitch-forming mechanism and the work after the sewing on the buttonhole has been completed thereby carrying the parts from stitching position to-buttonhole cutting position, such movement separating the stitched buttonhole from the throat plate. Dur-- ing this relative movement the thread or threads which lead from the under side of the work at the finishing point of the buttonhole are drawn through the throat plate and the tension to which the threads are subjected by being thus drawn through the throat plate is apt to pull the portion of the work to which said thread or threads are attached down into the sewing opening between the clamp plates. If this occurs there is a possibility that when the thread cutter is actuated to cut or trim the thread beneath the work ,cutter.

said cutter may injure the fabric or the last stitches of the buttonhole.

Another feature of my invention is the support of the work adjacent the finishing point of the buttonhole during the shifting of the parts from stitching position to buttonhole-cutting position thereby preventing the portion of the work at the finishing point of the buttonhole from being pulled .down into a position where it would be in danger of being injured by the operation of the The means for accomplishing this is in the form of a separating member lying against the work and which has an edge adjacent the finishing point of the buttonhole and across which edge the thread or threads leading from the under side of the work are laid by the relative movement of the parts from sewing position to buttonhole-cutting position whereby such separating member is interposed between the work and the thread. This edge of the member across which the thread or threads are laid constitutes a work-supporting edge which prevents the work from being pulled down out of place by any strain on the threads leading from the under side of the work.

In the illustrated embodiment of the invention this separating member is formed as part of the cutter by which the thread is trimmed beneath the work although so far as the operation of the separating member is concerned it is not essential that it should be formed as part of the cutter.

Still another feature of the invention relates to a novel method of severing the thread leading from the under side of the buttonhole, which method consists in producing a relative movement of the work and sewing mechanism at the end of the sewing operation on thebuttonhole thereby'shifting the parts from sewing position to cutting position and in so doing interposing a separating member between the work and the thread leading from the under side of the work and thereafter severing the thread at the finishing point of the buttonhole.

Other features of the invention relate to various improvements which will be more fully hereinafter set forth.

In order to give an understanding of the invention I have illustrated in the drawings a selected embodiment thereof which will now be de-v scribed after which the novel features will be pointed out in the appended claims.

Fig. 1 is a side view of a portion of a buttonhole sewing machine embodying my invention;

Fig. 2 is a front end view;

Fig. 3 is a top plan view of the upper thread pull-01f;

Fig. 4 is an under side view of the bed frame and stitch frame with parts shownin section;

Fig. 5 is a plan view of the turret carrying the under thread mechanism;

Fig. 6 is a plan view of the clamp plates showing the work clamps and the under thread an stay cord cutter;

Fig. 7 is a fragmentary view of the turret showing the position of the stay cord pull back during the sewing operation; I

Fig. 8 is a similar view showing the manner in which this pull back acts on the stay cord to position it for the formation of the first stitches of a sewing cycle;

Figs. 9, 10, 11 and 12 are views of the turret and illustrate the construction of the under thread gripping device, Figs. 9 and 10 showing the turret from two opposite sides and Figs. 11 and 12 showing the turret viewed from a position from that shown in Fig. 9.

Fig. 13 is a more or less diagrammatic view illustrating the operation of disrupting the upper thread;

Fig. 14 is a view showing the position of the threads at the end of the sewing cycle;

Fig. 15 is a similar view showing the position of the parts when they have been shifted from stitching to buttonhole-cutting position;

Fig. 16 is a fragmentary view illustrating the means for operating the under thread gripper device to release the thread to permit the extra length to be pulled back through the throat plate and also to release the thread after the stitching begins on the next buttonhole;

Fig. 17 is a fragmentary plan view illustrating the means that thus releases the thread gripper;

Fig. 18 is a fragmentary view of the throat plate showing the operation of gripping the under thread.

The sewing machine herein illustrated is of that known type in which the work is held by work-holding means mounted on a stationary bed frame and in which the stitch-forming mechanism is carried by a stitch frame which moves back and forth on the bed frame thereby to give the necessary feeding movement to form the stitches down one side of the buttonhole and back along the other side thereof. In these sewing machines the stitch frame has an additional movement after the stitching on any buttonhole has been completed for the purpose of separating the stitched buttonhole from the stitchforming mechanism and placing said buttonhole in proper position relative to the buttonhole-- cutting mechanism so that when the latter is actuated the buttonhole slit will be properly cut. In other words, this additional movement of the stitch frame carries the parts from stitching position to buttonhole-cutting position.

In the drawings the bed frame on which the work is supported is indicated generally at 1 and the work 2 in which the buttonhole is tobe sewed is held in position on said bed frame 1 by workholding means which comprise clamp plates 3 that are removably carried by the bed frame 1 as usual and work clamps 4 which clamp the work against the clamp plates, said work clamps being carried by the clamp arms 5 which are pivoted at 6 to the clamp plates as usual in devices of this type. I

The stitch-forming mechanism comprises the usual vertically-reciprocating needle 7 carrying the upper thread 8 and operating from above the work and looper mechanism indicated generally at 9 (see Fig. 10) which is mounted on a turret 10 situated beneath the work. This stitch-forming mechanism is carried by a frame 11 which,

for convenience, will be referred to as the stitch frame.

'journalled in the stitch frame and which carries at its upper end a segment gear 101 which meshes with a gear 102 by which the needle bar is rotated and which carries at its lower end another segment gear 103 which meshes with a gear 104 on the turret.

The rock shaft has an arm fast thereto which is connected by a link 106 to a lever 56 pivoted at 107. This lever is actuated by the main cam 16 which is enclosed within the cam casing 108 that is secured to the stitch frame, said main cam also controlling the other operations of the sewing machine, including the to and fro movement of the stitch frame on the bed frame, as usual in buttonhole sewing machines of this type.

The buttonhole-cutting mechanism comprises the usual buttonhole-cutting elements 17 and 18, both of which are carried by the stitch frame and one of which is situated beneath the work and the other of which is carried by a cutter lever 19 pivoted at 20 and having a tail portion 21 that is acted upon at the proper point in the buttonhole cycle, by a hump 22 carried by the main cam 16 thereby to give the cutter element 18 its buttonhole-cutting movement.

As stated above in the operation of these sewing machines the stitch frame 11 is given a to-andfro feeding movement during the formation of the buttonhole stitches in order to lay the stitches along the sides of the buttonhole and when the stitching on the buttonholev has been completed the stitch-forming mechanism is brought to rest with the needle 7 raised as shown in Fig. l and with a loop of the needle threadcaught on or retained by the looper mechanism 9. This is the position of the parts shown-in full lines in Fig. 1

and in Fig. 11.

Immediately after the stitch-forming mechanism comes to rest the stitch frame is given a further movement into the dotted line position Fig. l by which the stitch-forming mechanism is separated from the stitched buttonhole and the buttonhole-cutting mechanism is brought into position to cut the buttonhole slit. In other words, the parts are shifted from stitching position to buttonhole-cutting position.

Buttonhole sewing machines of this type are usually provided with means for cutting the threads at a point in the complete buttonhole cycle between the completion of the stitching and the end of the cycle when the complete machine comes to rest, and one feature of my present invention relates to an arrangement by which the upper thread will be broken by the tension placed on it during the movement of the stitch frame from stitching position to buttonhole-cutting position. By thus breaking the upper thread instead of cutting it the use of cutting mechanism for this purpose is eliminated and the construcp 7 1,988,460 tion of the buttonhole sewingmachine is thereby The turret 10 carries the usual throat plate or button" 23 which supports the work 2 at the sewing point, said throat having the sewing opening 24 therethrough through which the upper needle reciprocates and through which the under thread, indicated at 25, and stay cord, indicated at 26, are led to the work.

As stated above when the stitch-forming mechanism comes to rest at the end of a sewing operation on a buttonhole with the needle I raised as shown in Fig. 1 there will be a loop of needle thread retained by the looper mechanism 9, such loop being situated beneath the throat plate 23 and being indicated at 2'7 in Figs. 11 and 13.

One leg of said loop leads to the last stitch and the other leg passes through the work and leads to the needle 7. The needle thread 8 is subjected to the usual tension during the sewing operation through the medium of a tension device 28 which is shown in Fig. 1 as mounted on the top of the stitch frame. The needle thread comes from the source of supply, passes through the tension 28, thence through the take-up arm 29 and thence down through the hollow needle bar 12 to the needle 7. In the present invention the tension on the upper thread 8 of the tension device 28 is maintained not only during the formation of the stitches on the buttonhole but also during the movement of the parts from stitching position to buttonhole-cutting position.

The clamps remain closed while the stitch frame moves from stitching position to buttonhole-cutting position and during this movement not only will the needle '7 be moved forwardly from the last stitch as indicated by the dotted line position Fig. 1 but the throat plate 23 will also be carried forwardly ahead of the last stitch as shown by dotted lines in Fig. 13. During this forward movement of the throat and the needle, the loopers will, of course, apply an increasing tension on the loop 27 of needle thread and because the regular tension 28 is also applied to the needle thread between the needle and the source of supply and consequently no thread can be readily drawn through the tension 28 to accommodate the forward movement of the stitch frame, the loop of needle thread will be sub jected to sufficient tension to cause the thread to break. This breakage will invariably occur in the leg 30 of the loop 27 which leads to the last stitch and at the point where the upper thread is interlocked with other threads to form the last stitch. In other words, the upper thread will be broken at a point close to the work and this breakage will occur during the first part of the forward movement of the stitch frame fromstitching position to buttonhole-cutting position as seen in Fig. 13. It will be observed that the breaking or disrupting of the upper thread is caused solely by the relative movement between the stitch-forming mechanism and work-holding means since during such relative movement the thread is placed under an increased tension suflicient to break it.

This disrupting of the upper thread by breaking it instead of cutting it has the advantage that it obviates the necessity of thread-cutting mechanism for the upper thread and thereby simplifies the construction of the machine.

The present machine is also provided with means somewhat similar to those shown in Patent No. 1,844,426, dated February 9, 1932 for withdrawing the broken end 199. of the upper thread from the work and holding said end ready for the formation of the first stitch in the next buttonhole. This withdrawing of the broken end is accomplished by a pull-off arm 31 pivoted to the stitch frame at 32 and normally occupying the position shown in Figs. 1 and 2. The tip end of the arm is provided with a toe portion 33 having a rounded end 34 and with a small piece of felt 35. After the stitch-forming mechanism has come to rest but before the upper thread is broken the pull-off arm 31 is swung about its pivot 32 into the dotted line position Fig. 2, during which movement the rounded end 34 wipes by the portion of the upper thread 8 extending between the needle 7 and 'the work 2. The breaking of the upper thread occurs just after the pull-off arm has reached the dotted line position Fig. 2 and subsequently said arm is allowed to swing back into its full line position during which movement the portion of the upper thread extending between the needle '7 and the work 2 is caught on the finger 33 and the broken end 199 of the needle thread will be pulled out of the work. During this movement the thread becomes crowded between the felt 35 and the tip end of the finger and the friction of the felt is suflicient to hold the thread end lightly.

The means herein shown for operating the pull-off finger 31 are somewhat similar to those illustrated in the device covered by said Patent No. 1,844,426. The cutter lever 19 has a finger 98 extending forwardly therefrom which is adapted to engage the pull-off arm 31 when the cutter lever makes its buttonhole-cutting movement. This engagement of the finger 98 with the pull-off arm 31 swings the arm backwardly into the dotted line position Fig. 2.

This arm 31 is acted on by a spring 97 which normally tends to hold the arm in the full line position Fig. 2 and hence as the cutter lever 19 is raised the arm 31 will have its operative movement to withdraw the broken end 199 of thread from the work.

At the conclusion of the sewing operation, therefore, the end of the upper thread will be retained by the felt on the pull-off arm 31 as shown by dotted lines in Fig. 2 and the frictional grip which the felt has on the thread is sufiicient to hold the thread end for the formation of the first stitch at the beginning of the next buttonhole.

The machine herein shown is also provided with means for drawing a surplus of upper thread through the tension 28 during the sewing on the buttonhole and then giving up said thread before the stitching begins on the next buttonhole. Fromthis operation a certain amount of slack thread will be provided between the tension 28 and'the needle which is sufficient for forming the loop of needle thread involved in; making of the first stitch of the next'buttonhole. ,Before the first stitch on the buttonhole is made, therefore, there will have been sufiicient upper thread drawn through the tension 28 to provide for making this stitch and hence there will be no danger that during the formation of the first stitch the end of the upper thread will be drawn back through the work before the thread becomes firmly anchored in the work.

This drawing off of the surplus thread is provided for by a thread-controlling member 36 which is secured to the upper end of the needle bar 12. This member is quadrant-shaped with a peripheral flange 37 provided with a slot 38 through which the thread is led in its passage from the tension to the bore in the needle bar.

During the sewing on the first side of the buttonhole the thread-controlling device will be in the positionshown in full lines Fig. 3 so that the thread 8 will be led directly from the take-u 29 through the slot 38 to the needle bar. When' the needle bar is turned in rounding the eye end of the buttonhole the controlling device will be swung from the full to the dotted line position Fig. 3 and during this movement one end of the slot 38 will engage the thread and carry it into the dotted line position Fig. 3, in doing which the surplus or additional amount of thread will be drawn through the tension 28. The thread controller remains in this position until after'the stitch-forming mechanism has come to rest but before the machine starts on the next stitching operation the stitch-forming mechanism, including the needle bar, is returned to its normal position shown in full lines as will be understood by those skilled in the art, and during this return movement from the dotted to the full line position Fig. 3, the thread controller 36 gives up a surplus length of thread thus providing the necessary slack thread between the tension 28 and the needle to enable the first stitch of the next sewing operation to be formed without. drawing any thread through the tension.

As stated above after sewing on the buttonhole is completed the parts are shifted from stitching to buttonhole-cutting position thereby separating the stitched buttonhole from the throat plate, during which operation a length ofthe thread or threads leading from the under side of the work at the last stitch or finishing point of the buttonhole will be drawn through the sewing opening of the throat plate and the portion ofthe thread or threads extending from the last stitch to the throat plate will lie at an angle to the work. As the thread or threads are thus drawn through the throat plate they are subjected to some tension which tends to draw the portion of the work at the finishing point of the buttonhole downwardly below the supporting surface of the clamp plates and into a position where such portion of the work might be injured by the cutter when it trims the thread close to the work. To prevent this from happening there is provided a novelmeans in the formof a separating member which is designed to support the work at the finishing point of the buttonhole and prevent it from being pulled downwardly.

This separating member is formed with an edge that is situated adjacent the finishing point of the buttonhole and across which edge the thread leading from the under side of the work is laid during the relative movement by which the parts are shifted from stitching to buttonholecutting position. In this way the separating member is interposed between the work and the thread leading from the under side of the work and said edge across which the thread is laid serves to support the work at the finishing point of the buttonhole and prevents it from becoming injured by the operation of the cutter.

This separating member may be made in various ways and for illustrative purposes is herein shown as in the form of a blade and is also illustrated as forming part of the thread-cutting member by which the threads are cut beneath the work although so far as its function as a separating member is concerned it is not necessary that it should be made as part of the thread-cutting member.

In the particular embodiment of the invention v herein shown the under thread cutter comprises cutting member 39'which is situated above the clamp plates 3 but which operates beneath the work. Said cutter member is mounted on a. rock shaft 40 which is journalled in the bed plate and which has a thread-cutting movement from the full 4:0 the dotted line position Fig. 6 to effect the cutting of the under thread and stay cord. This thread-cutting member is formed with acutting edge 41 and with a finger 42 extending beyond the cutting edge. Said cutting member is also formed with a bridge portion formed by the edge 43 which is'on an arc struck from the rock shaft 40 as a center. This curved edge 43 is so positioned that when the sewing on the buttonhole is completed and the stitch-forming mechanism comes to rest the sewing opening 24 will be in close adjacency to said edge 43 as shown best in Fig. 6 and hence the threads extending from the under side of the work through the sewing opening 24, to wit, the under thread 25, the stay cord 26 and the two limbs-of the needle loop 27 will lie closely adjacent said edge 43 as seen in Fig. 14. In other words, the edge 43 is located adjacent the point where the sewing on the buttonhole ends, which point may, for convenience, be termed the finishing point of the buttonhole.

During the additional movement of the stitch frame by which the parts are carried from stitching position to buttonhole-cutting position (which is represented by the movement from the full to the dotted line position Fig. 1 or from the position shown in Fig. 14 to-that shown in Fig. 15), the clamps remain closed, the throat plate v23, as well as the needle 7, move forwardly, while the edge 43 remains stationary relative to the work and the threads extending from the-work through the throat plate are held firmly against said edge. The edge 43 is thus placed between the work and the threads leading from the under side of the work by the movement of the parts from stitching to buttonhole-cutting position. The portion of the cutter having ,the edge 43 thus constitutes a separating member which is interposed or placed between the work and the threads leading from the under side of the work by the relative movement of the parts which carry them from stitching position to buttonhole-cutting position.

Subsequent to this shifting movement from stitching to buttonhole-cutting position the cutter member 39 is given its thread-cutting movement during which the edge .43 moves along the threads which are in engagement therewith and the under thread and stay cord are gathered between the finger 42 and the edge 43 and will be cut by the co-operative action of the cutting edge '41 and the edge 44 of the opening 45 between the clamp plates. Before this thread-cutting opserves to hold the work in place while the under. thread is being out even though the clamps are released and furthermore the portion of the cutter which is provided with said edge 43 serves to support the work and prevent it from being pulled down into the opening between the clamp plates so that the work is-protected from being eration occurs the work clamps 4 are released so cut or injured by the action of the cutter when the latter is cutting the under thread and stay cord close to the work.

It will be understood that the upper thread will have been broken and withdrawn from the fabric by the upper pull-off 31 before the cutter member 39 is actuated to cut the under thread and stay cord.

The cutter 39 is actuated in a manner similar to that illustrated in above-mentioned Patent No. 1,846,398, that is by the mechanism which rotates the stitch-forming mechanism. I

The rock shaft 40 is shown as having an arm 46 rigid therewith which is situated beneath the bed plate and is adapted to be engaged by a pin 4'7 carried by a bar 48 that is arranged to have a transverse motion. At one end the bar is slotted as shown at 49 and said end of the bar is'guided by a screw or pin 50 which is attached to the bed frame 1 and extends through the slot. A spring 51 which is connected to the bar 48 tends nor mally to hold said bar in the position shown in Fig. 4. The other end of the bar is connected to a lever 52 pivoted at 53 to the bed frame 1 and at its rear end said lever has a catch 54 adapted to be engaged by a dog 55-carried by the end of the lever 56 by which the stitch-forming mechanism is given its rotative movement. a

At the end of the sewing operation the parts are in the position shown in full lines Fig. 4 but as the lever 56 is'turned to give the stitch-forming mechanism its rotative movement at the end of the sewing on the button-hole the dog 55 engages the catch 54 and swings the lever 52 clockwise Fig. 4 thereby moving the pin 4'7 to the right and causing it to engage the arm 46 and thereby turn the rock shaft 40 and give the thread cutter 39 its thread-cutting movement.

During the movement of the parts from buttonhole stitching to buttonhole cutting position the under thread and stay cord will be drawn through the sewing opening 24 of the throat plate 23 so that when said threads are out there will be extra length of both threads projecting through the sewing opening as shown at 5'7 and 58 in Fig. 15.

One feature of my present invention relates to novel means for controllingthe under thread between the time that it is cut and the time when the stitching begins on the next buttonhole so that said under thread will be in proper position to form correctly the first stitch of the succeeding buttonhole. For thus controlling the under thread I have provided a thread gripper adapted to grip the under thread after the length 57 has been pulled'out and have also provided means for momentarily releasing the gripping action on the under thread after the latter has been cut and simultaneously drawing back the extra length through the sewing opening of the throat plate, said gripper again becoming operative to grip the under thread and hold it until after the stitching has begun on the next buttonhole and the end of the under thread has been seeurelyanchored in the work. The thread-gripping device is then again actuated to permanently release the thread.

The under thread is led through the usual under thread tension 59 which is mounted on the turret 10 and thence through a guide 60 in the turret and from thence through an eye 61 formed on the end of a resilient pull back arm 62 and from said eye 61 the thread passes to the threaded looper of the looper 62 is made of spring wire which is shown as coiled mechanism 9. The pull back about a stud 63 carried by the turret 10. One end 64 of the wire engages a post 65 mounted on the turret and the other end forms the resilient arm 62. 1

66 is a stop member which is adjustably secured in place by the stud 63 and against which the arm 62 normally rests as shown in Fig. 5.

During the pulling out of the length 5'7 of under thread through the sewing opening 24 while the stitch frame is moving from stitching position to buttonhole cutting position the tension on the under thread will swing the pull-back arm 62 into the dotted line position Fig. 5 so that the under thread 25 will extend in a substantially straight line from the sleeve 60 to the threaded looper as shown by dotted lines Fig. 5. As soon as this length 5'7 of under thread has been drawn out as above described said under thread is gripped against the under face of the throat. This gripping of the thread is accomplished by a thread-gripping device similar to that shown in said Patent No. 1,846,398.

This gripper comprises a gripping finger '74 that is adapted to grip the under thread 25 between itself and the under side of the throat 23. This finger operates through an opening '75 formed in the standard '76 of the turret 10 and it is pivotally connected at '77 to an upright arm '78 that is secured to a block '79. The block '79 is pivoted to the turret at 80 and the swinging movement of the block swings the arm '78 from the position. shown in Fig. 11 to that shown in Fig. 12 and.

vice versa.

The block '79 is acted on by a spring 82 which normally tends to hold it in its operative position shown in Fig. 11. v

The gripping finger '74 is acted on by a pulling spring 81 which normally holds it against the lower edge of the opening '75. During the movement of the stitch frame from stitching position to buttonhole cutting position the arm '78 is-moved backwardly into the position shown in Fig. 12 and then is released. During its backward movement the spring 81 maintains the gripping finger in engagement with the lower edge of the opening '75. The-end of the gripping finger is thinner than the body portion thereof and hence as the finger moves backwardly into the position shown in Fig. 12'the upper surface of'the finger will be separated from the under side of the throat 23. This separating movement is suflicient to carry the end of the finger below the portion of the under thread 25 extending from the throat plate to the threaded looper.

As soon as the pivoted block 79 is released it is moved upwardly by the spring 82 thus carrying the gripper finger '74 forwardly and during this forward movement it will enter beneath the under thread 25 and the cam surface 83 on the under side of the gripper finger will by its en-' gagement with the lower edge of the opening '75 raise the gripper finger to grip the under thread between itself and the throat plate, all as described in said Patent No. 1,846,398. In the present invention this backward movement of the arm '78 is derived from the forward movement of the stitch frame as the parts are moving from stitching position to buttonhole-cutting position.

The bed frame 1 has an arm 84 secured to the under side thereof and this arm carries at its end a V-shaped projection'85'. The portion 15 of the stitch frame carries a stud 86 on which is mounted a hub 8'7. This hub has rigid therewith an arm 88 which carries 'a cam projection 89 that is adapted to be engaged by the projection 85 during the movement of the stitch frame from stitching position to buttonhole-cutting positionas shown in Fig. 12. This movement will depress the arm 88 against the action of the return spring 90.

The hub 87 has another arm 91 rigid therewith which is adapted to engage a curved arm 92 extending from the block 79. The raising of the arm 91 operates through the arm 92 to swing the block '79 backwardly and hence when'the projection 85 wipes over the cam projection 89 during the movement of the stitch frame from stitching position to buttonhole-cutting position, the block 79 will be swung backwardly into the position shown in Fig. 12. After the projection 85 9 passes the cam 89 the spring 82 will return the performing the gripping finger to its normal-position thereby thread-gripping operation as above described.

Hence when the under thread is cut as above described the gripping finger 74 will be holding the under thread from any backward movement due to the tension of the pull-back arm 62 so that temporarily the extra length 57 of under thread will be projecting through the sewing opening 24 of the throat plate. Before the sewing on the next buttonhole begins, however, the thread-gripping finger will be temporarily released to allow the pull-back arm 62 to pull the extra" length 57 of under thread back through the throat plate and thereby place the extremity of the under thread in proper position for the formation of the first stitches on the next buttonhole without leaving any projecting end to be afterwards trimmed off. This release of the thread gripper 74 is momentary, however, and after the length. 57 of thread has been pulled back through the throat plate the thread gripper again becomes active to grip the thread and hold it till after the first stitches on the next buttonhole have been formed.

For thus temporarily releasing the thread gripper to allow the under thread to be pulled back I have provided means which becomes operative during the' reverse turning movement of'the'turret which occurs between the completion of the stitching on one buttonhole and the starting of the stitching on the next buttonhole. When the stitching on any one buttonhole is completed the turret will be in the position shown in Fig. 4, but as will be understood by those skilled in the art, before the stitching on the next buttonhole is started the turret is given a reverse turning movement through about 180 to bring the stitchforming mechanism back into the correct position for the starting of the sewing on the buttonhole.

During such reverse movement the curved arm 92 will swing from the full to the dotted line posltion Fig. 4 and I. have provided means whereby during this reverse turning movement of the turret the thread gripper 74 will be temporarily released.

Secured to the portion 15 of the stitch frame is an arm 93 carrying a stud 94 having a rounded end 95. The curved arm 92 has a rib 96 at its end (see Fig. 16) and this rib and stud 94 are so positioned relatively that during the reverse turning movement of the turret by which the arm 92 is carried from the full to the dotted line position Fig. 4 the rib 96 will wipe over the rounded head 95 of the stud 94 thereby rocking the block 79 and moving the thread-gripping finger 74 backwardly. As soon as the rib 96 has wiped over the rounded head 95 the springs 81 and 82 will serve to ret.:n the gripping finger 74 to its threadgripping position. This movement of the arm 92 is illustrated in Fig. 17, it being the movement from the full to the dotted line position in said figure.

As soon as the thread gripper has released its grip on the thread the resiliency of the pull-back arm 62 causes it to move from the dotted to the full line position Fig. thereby drawing the extra length 57 of under thread back through the sewing opening of the throat plate as seen in Fig. 18. The stop 66 will be so adjusted that the pullback movement of the arm 62 will be sufficient to pull the under thread back into the. position shown in Fig. 18 in which position the extremity of the under thread will project slightly through the sewing opening of the throat plate. As soon as the under thread has thus been pulled back the thread gripper immediately becomes operative to again grip the under thread and this gripping action is maintained until after the stitching is begun on the next buttonhole.

When the first stitches are formed on any buttonhole the under thread will be properly presented for the formation of the first stitches without leaving a projecting end which has to be trimmed subsequently and the thread gripper acts during the formation of the first stitches to hold the under thread so that the first stitch can be properly formed. After the first stitches have been formed and the under thread has been anchored in the work then the gripper is again actuated to release its gripping hold on the under thread. Such actuation of the gripper is derived from the feeding movement of the stitch frame which occurs as the stitching begins and for this purpose the arm 92 is provided with an extension 97 and the bed frame 1 has secured to its under side an arm 98 carrying a stud 99 having a rounded upper end 109.

At the time the stitching begins on the buttonhole the turret is in a position to present the arm 92 and its projection 97 in the dotted line position Figs. 4 and 17. As the stitching begins on the next buttonhole the stitch frame moves toward the bottom of Fig. 4 and during such movement the extension 97 will wipe over the rounded end 109 of the stud 99 with the result that the arm 92 will be raised and the block 79 tilted thereby to release the gripper 74.

I have, therefore, provided a sewing machine in which at the end of the sewing operation a length of under thread is pulled through the throat plate and said under thread is gripped and after the thread is cut close to the work the gripping actionon the thread is temporarily released and the extra length is pulled back through the throat plate and the thread is then again gripped and the gripping action maintained until after the first stitches have been formed on the next buttonhole.

Thesewing machine herein shown also provides means for pulling back the extra end 58 of said cord 26 so that said end of the stay cord will be properly positioned for the beginning of the next stitching operation. The stay cord is led to the sewing opening through a guide opening in a finger 67 which is pivoted to the turret at 68 and which is acted on by a spring 69 that normally tends to hold it in its rearward position shown in Fig. 8. The spring 69 comprises a coiled portion 70 and the arm which extends between the finger 67 and a pin 71. The upper end of the finger 67 is provided with a gripping flange 72 and said finger carries a spring-gripping member 73. The cord 26 passes between the flange 72 and the finger 73. This finger 73 will yield to allow the cord to pass freely forwardly during the sewing operation but will prevent the cord from being pulled backwardly through the eye in the finger 6'7. I

During the sewing operation and also during the movement of the stitch frame from stitching to buttonhole-cutting position the tension on the cord 26 is suflicient to overcome the spring 69 so that the finger '67 will occupy the position shown in Figs. '7, 11 and 12. As soon as the cutter 39 operates to cut the under thread and stay cord then the tension of the spring 69 is sufiicient to swing the finger 6'7 backwardly into the position shown in Fig. 8 thereby drawing through the sewing opening of the throat plate the extra length 58 of stay cord and placing the extremity of the cord in proper position for the sewing on the next buttonhole. It-will be noted that the gripping device '73 which prevents retrograde movement of the cord 26 is operative at all times regardless of the position of the arm 67. In

. other words, this gripping member '73 is equally arm 67 is in its retracted.

operative when the position shown in Fig. 8 or in its forward position shown in Fig. '7. This gripping member, therefore, is operative at all times.

Hence with the construction herein illustrated the under thread 25 and the stay cord 26 areso manipulated at the end of the stitching operation that the ends of said threads will be properly positioned for forming the first stitch of a buttonhole without leaving any projecting ends which have to be subsequently trimmed ofi. The threads which extend from the under side of the work to the, sewing opening inthe throat plate include the under thread 23 and the cord 26. The term thread as used in the claims when referring to either of the threads which extends from the under sideof the work is intended to include either the under thread or the stay cord or both, each of which is properly defined as a thread.

I claim:

1. A buttonhole sewing machine of the type comprising work-holding means, stitch-forming mechanism including a needle operating above the work and carrying needle thread and a looper mechanism beneath the work and in which the stitch-forming mechanism comes to rest at the end' of the sewing operation with the needle raised and a loop of needle thread caught by the looper mechanism, the combination with said stitch-forming mechanism and work-holding means, of means to produce a relative movement between said stitch-forming mechanism and work-holding means after the sewing is com-' pleted, and means to cause the thread to be dis connected from the work solely by such relative movement.

2. A buttonhole sewing machine of the type comprising work-holding means, stitch-forming mechanism including a needle operating above the work and carrying needle thread and a looper mechanism beneath the work and in which the stitch-forming mechanism comes to rest at the end of the sewing operation withthe needle raised and a loop of needle thread caught by the looper mechanism, the combination with said stitch-forming mechanism and work-holding means, of means to produce a relative movement between said stitch-forming mechanism and work-holding means after the sewing is completed, and means to subject the thread during such relative movement to suilicient tension to break the thread close to the work.

mechanism beneath the work and in which the stitch-forming mechanism comes to rest at the end of the sewing operation with the needle raised and a loop of needle thread caught by the looper mechanism, the combination with said stitchforming mechanism and work-holding means, of means to produce a relative movement between said stitch-forming mechanism and work-holding means after the sewing is completed, means to cause the needle thread to be disrupted at a point beneath the work solely by such relative movement, and means operating above the work to hold the disconnected end of upper thread.

4. A button hole sewing machine of 'the type comprising work-holding means, stitch-forming mechanism including a needle operating above the work and carrying needle thread and a looper mechanism beneath the work and in which the stitch-forming mechanism comes to rest at the end of the sewingoperation with the needle raised and a loop of needle thread caught by 5. A button hole sewing machine of the type- I comprising work-holding means, stitch-forming mechanism including a needle operating above the work and carrying needlethread and a looper mechanism beneath the work and in which the stitch-forming mechanism comes to rest at the end of the sewing operation with the needle raised and a loop of needle thread caught by the looper mechanism, the combination with said stitch-forming mechanism and work-holding means, of means to produce a relative movement between said stitch-forming mechanism and work-holding means after the sewing is' completed on a button hole to carry the .parts from stitching position to buttonhole-cutting position, and a tension device by which a tension is continuously applied to the needle thread, whereby during such relative movement the strain placed on the needle thread will break it at the point where one leg of said loop is attached to the work. I

6. A buttonhole sewing machine of the type comprising work-holding means, stitch-forming mechanism including a needle operating above the work and carrying needle thread and a looper mechanism beneath the work and in which the. stitch-forming mechanism comes to rest at the means to produce a relative movement between said stitch-formingmechanism and work-holding means after the sewing is completed on a buttonhole to carry the parts from stitching position to buttonhole-cutting position, a tension device by .which a tension is continuously applied to the needle thread, whereby during such relative movement the strain placed on the needle thread will. break it at the point where one leg of said loop is attached to the work, and means operating above the work for pulling the broken end of the needle thread back through the work.

7. A buttonhole sewing machine of the type comprising work-holding means, stitch-forming mechanism including a needle operating above the work and carrying needle thread and a looper mechanism beneath the work and in which the stitch-forming mechanism comes to rest at the end of the sewing operation with the needle raised and a loop of needle thread caught by the looper mechanism,thecombinationwithsaidstitch-forming mechanism and work-holding means, of buttonhole-cutting mechanism, means to produce a relative movement between said stitch-forming mechanism and work-holding means after the sewing is completed on a buttonhole to carry the parts from stitching position to buttonhole-cutting position, a tension device by which a tension is continuously applied to the needle thread, whereby during such relative movement the strain placed on the needle thread will break it at the point where one leg of said loop is attached to.

the work, and means controlled by the buttonhole-cutting mechanism to pull the broken end of needle thread back through the work.

8. In a buttonhole sewing machine, the combination with stitch-forming mechanism and work-holding means, said stitch-forming mechanism comprising a needle operating above the work and carrying needle thread, of means to produce a relative movement between said stitchiorming mechanism and work-holding means after the completion of the sewing on a buttonhole'thereby to carry the parts from stitching to buttonhole-cutting position, means for disrupting the needle thread close to the work during such relative movement, a pull-off arm having a thread-engaging finger at its end, and a felt disk secured to said arm adjacent said finger, and means to actuate said pull-oil arm to cause the needle thread to be engaged between said finger and disk, whereby the movement of the arm pulls the disrupted end of the needle thread back from the work and holds it ready for the formation of the first stitch in .the next buttonhole.

9. In a buttonhole sewing machine,.the combination with work-holding means, of stitch-- forming mechanism comprising a needle operating from above the work and a turret beneath the work carrying a throat plate having a sewing opening, a thread-cutting member situated beneath the work and operating between said throat plate and the work, means to move the stitchforming mechanism and work-holding means relatively after the completion of the sewing on 'a buttonhole thereby to draw out a length of thread through said throat plate, said threadcutting member having an edge situated adjacent the last stitch and around which the thread is drawn during such relative movement, and means to actuate the thread-cutting member/to cut the thread.

. 10. In a buttonhole sewing machine, the combination with work-holding means, of stitchforming mechanismcomprising upper thread mechanism and under thread mechanism, a tin-- ret beneath the work carrying said under thread mechanism, said turret having a throat plate through which the under thread is led to the work, means to .give'the stitch-iorming mechanism and work-holding means a relative movement after the completion of the sewing thereby back through the throat plate said length of under thread during themomentary cessation of the gripping action of the thread gripper.

11. In a buttonhole sewing machine, the combination with work-holding means, of stitchforming mechanism comprising upper thread mechanism and under thread mechanism, a turret beneath the work carrying said under thread mechanism, said turret having a throat -plate through which the under thread is led to the work, means to give the stitch-forming mechanism and work-holding means a relative movement after the completion of the sewing thereby to draw out a length of under thread through the throat plate, means to cut the under thread close to the work after it has been thus drawn out, a thread-gripping device, means to actuate the thread-gripping device to grip the under thread before the latter is cut, means to cause the thread-gripping device to momentarily release its gripping engagement with the thread and then to grip the thread again after the thread has been cut, means acting on the thread to pull back through the throat plate a length of thread when the gripping pressure is thus released, and means to release the engagement of the thread-gripping device with the thread after the sewing has started on the next buttonhole.

12. In a buttonhole sewing machine, the combination with work-holding means, of under thread mechanism, a rotary turret beneath the work carrying said under thread mechanism and provided with a throat through which the under thread is led to the work, means for producing a relative movement between said work-holding means and. turret after-the completion of the stitching on a buttonhole thereby to draw out a length of under thread through said throat, means to out said under thread close to the work, a thread-gripping device, means to actuate the same to grip the under thread before the latter is cut, means rendered operative by the rotation of the turret to momentarily release the gripping engagement of the thread with the gripper after the thread is cut, automatically-operative means to pull said length of thread back through the throat when. said gripping engagement is thus momentarily released, and means to again release the gripping action on the thread after the stitching has begun on the next buttonhole.

13. In abuttonhole sewing machine, the combination with work-holding means, of under thread mechanism, a rotary turret beneath the work carrying said under thread mechanism and provided with a throat through whichthe under thread is led to the work, means for producing a relative movement between said work-holding means and turret after the completion of the stitching on a buttonhole thereby to draw out a length 01' under thread through said throat,

pletion of the sewing on a to pull said length of thread back through the throat when said gripping engagement is thus momentarily released, and means rendered operative by said relative movement to again release the gripping action on the thread after the stitching has begun on the next buttonhole.

1a. In a buttonhole sewing machine having stitch-forming mechanism and work clamps for holding the work during the stitching on the buttonhole but which are released when the stitching is completed, the combination with said stitch-forming mechanism and work clamps, of a turret beneath the work carrying a throat plate having a sewing opening, a thread-cutting member operating between said throat plate and the work, means to move the stitch-forming mechanism and work-holding means relatively after the completion of the sewing on the buttonhole thereby to draw out a length of thread through. said throat plate, said thread-cutting member having an edge situated adjacent the last stitch and around which the thread is drawn during such relative movement, the tension on the thread caused by this relative movement and the engagement of said thread with said edge holding the work in position, and means to actuate the thread-trimming member to cut the thread after the work clamps have opened.

15. In a buttonhole sewing machine, the com bination with work-holding means including work clamps which are opened after the completion of the sewing on a buttonhole, of stitchforming mechanism including upper and under thread mechanism, a turret beneath the work carrying the under thread mechanism and pro vided with a throat plate having a sewing opening, a pivoted thread-cutting member operating between the throat plate and the work, said thread-cutting member having an edge formed on an arc struck from its axis. of movement and situated adjacent the last stitch on the buttonhole, means to move the stitch-forming mechanism and work-holding means relatively after the completion of the sewing on a buttonhole thereby to draw out a length of thread through said throat, which thread is drawnaround said edge, the latter serving to hold the work in position during the thread drawing operation, and

means to actuate the thread cutter went the thread.

16. In a buttonhole sewing machine, the combination with work-holding means including work clamps which are opened after the completion of the sewing on a buttonhole, of stitchforming mechanism including upper and under thread mechanism, a turret beneath the work carrying the under thread mechanism and provided with a throat plate having a sewing opening, a pivoted thread-cutting member operating between the throat plate and the work, said thread-cutting member having an edge formed on an arc struck from its axis of movement and situated adjacent the last stitch on the'buttonhole, means to move the stitch-forming mechanism and.wcrk-holding means relatively after the. completion of the sewing on a buttonhole thereby to draw out a length of thread through said throat, which thread is drawn around said edge, the latter serving to hold the work in position during the thread-drawing operation, and means to actuate the thread cutter to cut the thread after the clamps have been raised.

17. In abuttonhole sewing machine, the comvbination with work-holding means including work clamps which are opened after the combuttonhole, of stitchcutting edge in an arc. struck from the axis of said member, said work-supporting edge being situated adjacent the last stitch, means to move the stitch-forming mechanism and work-holding means relatively after the completion of the sewing on a buttonhole but before the clamps are opened thereby to draw out a length of thread through said throat and around said work-supporting edge, the latter serving to support the work during this operation, and means to actuate the cutter to cut the thread.

18. In a buttonhole sewing machine, the com-, bination with work-holding means, of stitchforming mechanism including under thread mechanism, a throat plate through which the under thread is led to the work, means for moving the stitch-forming mechanism and workholding means relatively after the completion of the .sewing on a buttonhole thereby to draw out a length of thread through the throat plate, a one-way thread-gripping means operative at all times to prevent retrograde movement of the thread while permitting the thread to be freely fed forward, means to cut the thread, and means co-operating with said thread-gripping means to pull the thread back through the throat plate thereby to provide the proper length of thread for the start of the stitching on the next buttonhole without leaving a projecting end.

19. In a buttonhole sewing machine, the combination with work-holding means, of stitchforming mechanism including under thread mechanism, a turret carrying said under thread mechanism and having a throat plate provided. with a sewing opening through which the under thread and stay cord is led to the work, .means for moving the stitch-forming mechanism and work-holding means relatively after the completion of the sewing on a buttonhole thereby to draw out a length of under thread and stay cord through the throat plate, means to cu'tsaid thread and stay cord close to the work, pullback means acting on through the sewing opening a length drawn therethrough by the above=mentioned relative movement, whereby the stay cord is properly presented for the first stitches on the next buttonhole, and means operative independently of the operation of the pull-back means to prevent retrograde movement of the stay cord relative to said pull-back means.

20. In a buttonhole sewing bination with work-holding machine, the commeans,. of stichforming mechanism including under thread a turret carrying said under thread havinga throat plate provided with. a sewing opening through which the under thread and stay cord is led to the work, means for moving the stitch-forming mechanism and mechanism, mechanism and work-holding means relatively after the comthe stay cord to pull back cord is properly presented for the first stitches on the next buttonhole, and means operative in all positions of the pull-back arm to prevent retrograde movement of the stay cord relative to said arm.

21. In a buttonhole sewing machine, the combination with work-holding means, of stitchforming mechanism including under thread mechanism, a turret carrying said under thread mechanism and having a throat plate provided with a sewing opening through which the under thread and stay cord are led to the work, means for moving the stitch-forming mechanism and work-holding means relatively after the completion of the sewing on a buttonhole thereby to draw out a length of under thread and stay cord through the throat plate, means to out said thread and stay cord close to the work, a spring-actuated arm pivoted to the turret and provided with an eye through'which the stay cord passes, means carried by said arm to prevent retrograde movement of the stay cord through said eye, feeding movement of the stay cord during sewing on the buttonhole swinging the arm toward the throat against the action of its spring, whereby when the stay cord is out said arm automatically pulls back through the sewing opening a length of stay cord which was drawn through said opening during such relative movement.

22. In a buttonhole sewing machine, thecombination with work-holding means, of stitchforming mechanism including under thread mechanism, a throat plate provided with a sewing opening through which the under thread and stay cord is led to the work, means for moving the stitch-forming mechanism and work-holding means relatively after the completion of the sew ing on a buttonhole thereby to draw out a length of under thread and stay cord through the throat plate, means to out said thread and stay cord close to the work, pull-back means acting on the stay cord after it is cut to pull back through the sewing opening a length drawn forwardly therethrough by the above-mentioned relative movement, and means also acting on the stay cord which permits. free forward movement thereof but prevents retrograde movement relative to the pull-back means, said last-named means being operative independently of the action of the pullback means.

23. In a sewing machine of the type having stitch-forming mechanism which comprises a needle operating above the work and which comes to rest at the end of the sewing operation with the needle raised and aloop of needle thread held by the loopers, the combination with said stitch-forming mechanism, of work-clamping means, a tension for the needle thread which continuously applied, and means operative automatically at the end of the sewing operation and while the work is clamped to subject the needle thread to suilicient tension to break said thread at the point where it is interlocked with the last stitch.

24. In a sewing machine of the type having stitch-forming mechanism which cor'npri'ses a. needle operating through the work, the combination with said stitch-forming mechanism, of

work-clamping means, means to apply tension.

to the needle thread, and means operative automatically at the end of the sewing operation and while the work is clamped to subject the needle thread to suflicient tensional strain to-break said thread at the point where it is interlocked with the last stitch.

operating through the work and which comes to rest at the-end of the sewing. operation with theneedle withdrawn from the work, the combination with said stitch-forming mechanism, of a tension device for the needle thread, and means operative automatically at the end of the sewing operation to apply to the needle thread a suflicient pulling strain in a direction at an angle to the plane of the work to break the thread at the point where it is interlocked with the last stitch.

26. In a buttonhole sewing machine, the combination with stitch-forming mechanism and work-holding means which have a relative movement at the end of the sewing to carry the parts from stitching position to buttonhole-cutting position, of a throat plate through which the under thread is led to the work, such relative movement drawing out a length of thread through the throat plate and a movable member which is stationary relative to the work during the drawing out of said thread and which is placed between the throat plate and the work by such relative movement.

2'7. In a buttonhole sewing'machine, the combination with stitch-forming mechanism and work-holding means which have a relative movement at the end of the sewing to carry the parts from stitching position to buttonhole-cutting position, of a throat plate through which the under thread is led to the work, such relative movement drawing out a length of thread through the throat plate and a member which is stationary relative to the work duringthe .drawing out of the thread and which is placed between the throat plate and the work by such relative movement, said member having a thread-engaging edge extending transverse to such relative movement and with which the under thread and stay cord are brought into engagement by such relative movement.

28. In a buttonhole sewing machine, the combination with stitch-forming mechanism, of workholding means, a throat plate through which the thread is led to the work, said stitch-forming mech nism and work-holding means having a relative movementat the end of the sewing by which the thread is extended from the throat plate to'the surface of the work at an acute angle, and thread-cutting mechanism, a part of which is stationary relative to the work and is located to be included in said angle by such relative mo've ment and before the cutting takes place.

29. In a buttonhole sewing machine, stitchforming'mechanism, means for producing a relative movement between the stitch-forming mechanism and the work, and a movable member having an edge extending transversely to the line of buttonhole stitching, which memberfis stative movement between the stitch-forming mech-' anism and the work duringeach buttonhole forming cycle, a movable member having an edge extending transversely to the line of buttonhole stitching, and means to position said member between the under thread and the work, said member being stationary relative to the work while being so positioned.

inse m 31. In a buttonhole sewing machine which sews a buttonhole and then comes to rest, in combination, stitch-forming mechanism, a throat plate through which thread is led to the work,

a movable member having an edge extending transversely to the line of stitching, and means to position said member over the throat plate in the interval of time between the formation of the last stitch and the stopping of the machine, said member being stationary relative to the work while being thus positioned.

32. In a buttonhole sewing machine, in com bination, stitch-forming mechanism, workclamping means, said stitch-forming mechanism and work-clamping means having a relative movement at the completion of the sewing by which the thread is extended at an acute angle to the surface of the work, and thread-cutting mechanism, part of which is located to be in cluded in saidangle by such relative movement after the sewing is completed and before the cutting of the thread takes place and is stationary relative to the work while being so located.

33. In a buttonhole sewing machine, stitchforming mechanism, means for producing relative movement between the stitch-forming mechanism and the work, and a thread-cutting member having an edge extending transversely to andnormally across the line of buttonhole stitching, which member is positioned between the work and the thread leading from the under side thereof before the work is unclamped.

34. In a buttonhole sewing machine, stitchforming mechanism, work-clamping means, a

thread-cutting member having an edge extend-, ing transverselyito and normally across the line of buttonhole stitching, and means to position said member between the under thread and the work before the work is unclamped.

35. In a buttonhole sewing machine that sews a buttonhole and then comes to rest, in combination, stitch-forming mechanism, work-clamping means, a throat plate through which thread is led to the work, a thread-cutting member having an edge extending transversely to the line of stitching, and means to position saidmember over the throat plate before the work is unclamped.

36. A buttonhole sewing machine having stitch-forming mechanism, work-clamping means for clamping the work each side of the buttonhole slit and provided with a sewing opening in line with said slit, 2. throat plate through which under thread is led to the work, said stitchforming mechanism and work holding means having a-relative movement after the completion of the sewing by which a length of thread is drawn through the throat plate, a thread-cutting member having a work-supporting edge extending transverselyto the line of the buttonhole slit, and means whereby said member is placed between the work and the thread leading from the under side thereof after the completion of the stitching but before the work is unclamped, said work-supporting edge preventing the work from being drawn into the sewing opening by the tension applied to the thread.

3?. A buttonhole sewing machine having stitch forming mechanism, work clamping means for clamping the work each side of the buttonhole slit and provided with a sewing open-= ing in line with said slit, a throat plate through which under thread is led to the work, said stitch- Iorming mechanism and work-holding means work-clamping means,

having a relative movement after the completion drawn through the throat plate, a thread-cutting member having a work-supporting edge extending transversely to the line of the buttonhole slit, means whereby said member is placed between the work and the thread leading from the under side thereof after the completion of the stitching but before the work is unclamped, and means operating above the sewing opening to out the thread, said work-supporting edge preventing the work from being drawn into the sewing opening as the thread is drawn through the throat plate.

38. In a buttonhole sewing machine, the combination with work-holding means, of stitchforming mechanism, means for producing a relative movement between the stitch-forming mechanism and the work-holding means, and a thread-trimming knife situated transversely to the line of stitching and which is placed between the thread and/or cord to be trimmed and the work by such relative movement, said knife being held from movement relative to the work-holding means in the directionof the length of the buttonhole. 39. In a buttonhole sewing machine, in combination, sewing mechanism, a buttonhole cutter, means for shifting the parts from sewing position to buttonhole-cutting position, a separating member having an edge adjacent the finishing point of the buttonhole and across and in engagement with which edge thethread is laid by the relative movement of the parts from sewing position to buttonhole-cutting position, whereby the separating member is interposed between the work and thread, and means for cutting the thread near the finishing point of the buttonhole.

40. In a buttonhole sewing machine, in combination, stitch-forming mechanism, a buttonhole cutter, means for shifting the parts from sew.ng

position to buttonhole-cutting position, a separating member beneath the work and having an edge adjacent the finishing point of the buttonhole across and in engagement with which edge the thread leading from the under side of the work is laid by the relative movement of the parts from sewing position to buttonhole-cutting position, whereby the separating ,member is interposed between the work and the thread, and means for cutting the thread near the finishing point of the buttonhole,

$1. In a buttonhole sewing machine, stitchforming mechanism, work-holding means, a buttonhole cutter, meansiior shifting the parts relatively from stitching position to buttonhole-cutting position, and a separating member having an edge extending transverselyto the direction of relative shifting movement and situated adjacent the finishing pointof the buttonhole andacross and in engagement with which edge the'thread leading from the under side of the work is laid by such shifting movement.

42. In a buttonhole sewing-machine, stitchforming mechanism, work-holding means, a buttonhole cutter, means for shifting the parts relatively from stitching position to buttonhole-cut- .ting position, a separating member having any edge extending transversely to the direction of relative shifting movement and situated adjacent the finishing point of the buttonhole and across and in engagement with which edge the thread leading from the under side of the work is laid by such shifting movement, and means .of the sewing by which a length of thread is to cut the thread near the finishing point of the buttonhole.

43. The method of severing the thread from a finished buttonhole in a piece of work which consists in relatively moving the work and thesewing mechanism from sewing position to buttonhole-cutting position and during such relative,

movement maintaining a separating member in position with its edge closely adjacent the finishing point of the buttonhole thereby interposing said separating member between the work and the threadleading therefrom and causing the thread to be laid around and in engagement with said edge and thereafter severing the thread at the point of the buttonhole.

44. The method of severing the thread leading from a finished buttonhole in a pieceof work to the sewing mechanism, which consists in relatively moving the work and the sewing mechanism and thereby moving said thread to carry it aroundand in engagement with a separating member which is thereby placed between the work and the thread and subsequently severing the thread at the finishing point of the buttonhole.

45. In a buttonhole sewing machine, in combination, sewing mechanism, a buttonhole cutter,

means for shifting the parts from sewing position to buttonhole-cutting position, a separating member having an edge situated adjacent the finishing point of the buttonhole and in such position that the thread is laid across and in engagement therewith by the relative movement of the parts from sewing position to buttonhole-cutting position and the separating member is interposed between the work and the thread, and means for cutting the thread near the finishing point of the buttonhole.

46. In a buttonhole sewing machine, in combination, sewing mechanism, a'buttonhole cutter, means for shifting the parts from sewing position to button-hole-cutting position, a separating member having an edge situated adjacent the finishing point of the buttonhole and in such position that'the thread is laid across and in engagem'ent therewith by the relative movement of the parts from sewing position to buttonholecutting position and the separating member is interposed between the work and the thread, and means to cut the thread at the point where it engages said edge.

4'7. In a buttonhole sewing machine, in combination, stitch-forming mechanism, a buttonhole cutter, a separating-member beneath the work and having an edge adjacent the finishing point of the buttonhole, means for shifting the parts from sewing position to buttonhole-cutting position and thereby laying the thread leading from the under side of the work across said edge and interposing the separating member between the thread and the work, and means for cutting the thread at the point where it crosses said edge.

48. In a buttonhole sewing machine, stitchforming mechanism, work-holding means, a buttonhole cutter, means for shifting the parts relatively from stitching position to buttonhole-cutting position, a separating member having an edge extending transversely to the direction of relative shifting movement and situated adjacent the finishing'point of the buttonhole and across which the thread leading from the under side of the work is laid by such shifting movement, and means to cut the thread at the point where it crosses said edge.

49. A buttonhole sewing machine having stitch- ,forming mechanism and work-holding means shiftable relative to each other at the end of the sewing to carry the parts from stitching posi-.

tion to buttonhole-cutting position, a throat plate through which the thread is led to the under side of the work, a separating member having an edge extending transversely to the direction of such relative shifting movement and situated closely adjacent the finishing point of the buttonhole, and means to produce such relative shifting movement and thereby lay the.thread extending from the work to the throat plate across such edge and in engagement with said separating member.

JOSEPH PIKUL. 

